Latest Maastrichtian pachydiscid ammonites from The Netherlands and Poland

Marcin Machalski, John W.M. Jagt

Abstract


The pachydiscid ammonite Menuites terminus (WARD & KENNEDY, 1993) is described from the uppermost Maastrichtian deposits in the type area of the Maastrichtian Stage in southeast Netherlands (upper part of the Meerssen Member of the Maastricht Formation) and in central Poland (upper part of the Kazimierz Opoka). Variation in whorl section and ribbing in the material studied is documented. The presence of M. terminus places the upper parts of the Meerssen Member and of the Kazimierz Opoka in the highest Maastrichtian ammonite zone, the M. terminus Zone, defined originally in the Bay of Biscay region, and shows them to be equivalent to the interval from the upper part of Member IV to the top of Member V in the Bay of Biscay region. In the Maastricht area, the FAD (first appearance datum) of M. terminus approximately coincides with that of the latest Maastrichtian index belemnite Belemnella kazimiroviensis (SKOŁOZDRÓWNA, 1932). In Poland, the FAD of M. terminus is distinctly higher than that of B. kazimiroviensis, the latter species first appearing in the upper portion of marls underlying the Kazimierz Opoka.

Full Text:

PDF